Sand bin and drier



May 8, 1951 J. P. BRUNSCHWYLER SAND BIN AND DRIER Filed May 25, 1948 ETSAND BIN INVENTOR. JOHN P. BRUNSCHWYLER ELEVATOR CONVEYOR ATTORNEY.

Patented May 8, 1951 SAND BIN AND DRIER John P. Brunschwyler, Welch, W.Va., assignor to Allied Chemical & Dye Corporation, New York, N. Y., acorporation of New York Application May 25, 1948, Serial No. 29,062

4 Claims.

This invention relates to drying non-absorbent wet granular material andmore particularly refers to a new and improved method and apparatus fordrying wet sand.

An object of the present invention is to provide a continuous method foreconomically and effectively drying wet sand.

Another object of the invention is to provide an apparatus of economicalconstruction which is simple and eiiicient in operation.

Further objects and advantages will be apparent from the description andaccompanying drawings.

A method for drying wet sand in accordance with the present inventioncomprises introducing wet sand into the top of a vertical dryingchamber. passing the wet sand downwardly countercurrent to and inindirect heat exchange with hot gases, passing the sand through bafllesadapted to retard the how of sand, thence passing the sand through ahorizontal row of spaced tubes, said spacing between adjacent tubesbeing sumcient to permit grains of dry sand to pass but withoutpermitting agglomerations of wet sand pass therethrough, passing drysand into a dry sand bin, discharging the dry sand from said dry sandbin, introducing hot gases into said row of horizontal tubes, thencepassing said gases through a conduit upwardly in indirect heat exchangewith the downwardly moving mass of wet sand contained in said verticaldrying chambar and surrounding said conduit, and withdrawing water vaporevolved from said wet sand through orifices in said conduit.

In accordance with the invention, I provide apparatus involving thecombination of a vertical drying chamber adapted to receive wet granularmaterial at its upper end, a dry bin for receiving dry granular materialfrom said vertical drying chamber extending from and disposed beneathsaid vertical drying chamber, means for efiecting the release of drymaterial from said dry bin, a horizontal row of tubes having spacesbetween adjacent tubes sufiicient to permit only the passage of grainsof dry material therethrough intermediate said vertical drying chamherand dry bin, baffle means disposed above said tubes adapted to retardthe flow of wet material, a source of hot gases external of saidvertical chamber and dry a. conduit for conducting said hot gases fromsaid source to said tubes, a ertical extending upwardly through saidvertical chamber adapted to receive said hot gases from said tubes, andshielded spaced orifi-ces in said stack for removal of water vaporevolved from said wet material.

In the practice of my invention, I have thoroughly dried wet sand with amaterial reduction in labor and fuel required by conventional methods.My process and apparatus for drying wet sand also minimizes the exposurehazard occurring in the manual handling of sand.

In the accompanying drawings illustrating my invention:

Figure .1 is a front elevation in partial section of my improved dryer.

Figure 2 is a cross sectional view taken'on line 22 of Figure l in thedirection of the arrows.

Referring to Figure 1, wet sand from pit I is lifted by conventionalelevator conveyor 2 which may be a bucket elevator with metal links orbuckets fastened to the belt or it may be an elevator similar to the.Redler type. From the top of elevator 2, wet sand discharges onto chute3 into wet sand bin or drying chamber 4. The rate of introduction of wetsand into chamber 4 is preferably regulated to maintain a sand leveltherein at a short distance below the bottom of chute 3 thereby exposinga greater wet sand surface to indirect heat contact with hot gases inthe stack and thus more efliciently utilizing the heat content of thegases.

Wet sand 5 in chamber 4 moving downwardly by gravity becomes heated bythe countercurrent flow of hot combustion gases rising in stack 6causing water in the wet sand to vaporize. Normally, this water vaporwould tend to rise against the impediment of packed sand above it and asthe water vapor passes upward it would recondense by contact with coolersand thus preventing the release of Water from the body of sand.

to facilitate the withdrawal of water evolved from the wet sand, I haveprovided a series of orifices or holes i at intervals in the length. ofstack 6. The draft in stack 6 will exert a positive suction in pullingin water vapor through orifices I. Plugging of holes I may be avoided byplacing shields 8 in the form of skirts around stack 1 to separate theholes from the surrounding sand.

Near the bottom of chamber 4 are a series of horizontal deflectors orbafiles 9 which may desirably be fabricated from angle iron and placedin an inverted V position. Baflies 9 are spaced to prevent a largeamount or large agglomerations of sand falling on the tubes withconsequent choking up of passageways between them.

Beneath baffles 9 are two rows of parallel horizontal metal tubesconnected to common plenums I I and !2. The upper layer of tubes 13 arewidely spaced and the lower layer of tubes It carefully spaced to permitgrains of dry, sand to pass through but without permittingagglomerations 3 of wet sand to enter dry sand bin l5. While I prefer toutilize two rows of tubes as just described, I may employ one or threeor more rows of tubes providing at least one row of tubes is properlyspaced to permit the passage only of grains of dry sand.

The rate of discharge or dry sand from dry bin l5 onto truck l6 may beregulated by turning wheel I! which controls the size of the aperture atthe bottom of bin I5.

Heat for drying sand may be obtained from any hot gases from anysuitable external source. I prefer to employ the products of combustionfrom any available fuel such as natural gas and oil generated forexample in a hand fired furnace or combustion gas from burning anyavailable carbonaceous fuel in for example a small stoker. Combustiongases generated in furnace 68 are conveyed through insulated flue isinto plenum H, thence through parallel tubes [3 and 14 into plenum l2from which it discharges directly into the bottom of stack 6. Ifdesired, the position of stack 6 in chamber 4 may be shifted to a pointmore remote from plenum (2, in which event a duct, not illustrated, forconducting the gases from plenum 12 to the bottom of stack 6 would beemployed.

Figure 2 illustrates in more detail the relative position of baflies 9,tubes I3 and tubes M. It will be noted that baifles 9 prevent the largemass of sand in chamber 4 from pressing down onto tubes I3 and 14thereby aiding in the avoidance of jamming the passageways betweenadjacent tubes. More widely spaced tubes i3 effect a preliminary dryingof wet stand and a screening of agglomerations of wet sand. Final dryingand screening of the sand is accomplished in closely spaced tubes [4.

The details of construction of the apparatus will of course depend tosome extent upon the coarseness of the sand to be dried, its watercontent, degree of drying desired, etc. I have satisfactorily driedcoarse wet sand containing 25% by weight water with tubes 13 having anoutside diameter of 4 inches and spaced 8 inches from center to center;tubes 14 having an outside diameter of 4 inches and spaced 4% inchesfrom center to center, and rows of inch diameter holes I around thecircumference of stack 6, each row spaced about 70 inches along thelength of stack 6.

Although a preferred embodiment of the invention has been disclosed forpurposes of illustration, it will be evident that various changes andmodifications may be made therein without departing from the scope andspirit of the invention.

I claim:

1. A dryer for drying wet granular material, including in combination avertical drying chamber adapted to receive wet granular material at itsupper end, a row of tubes having spaces between adjacent tubessufiicient to permit only the passage of grains of dry materialtherethrough disposed at the bottom of said chamber, a source of hot gasexternal of said vertical chamber, a conduit for conducting said hotgases from said source to said tubes, a second conduit in communicationwith the discharge end of said tubes extending upwardly through saidvertical chamber, and shielded spaced orifices in said second conduitfor removal of vapor evolved from said wet material.

2. A dryer for drying wet granular material, including in combination avertical drying chamber adapted to receive wet granular material at itsupper end, a row of tubes having spaces between adjacent tubessufiicient to permit only the passage of grains of dry materialtherethrough disposed at the bottom of said chamber, bafile meansdisposed above said tubes adapted to retard the flow of wet material, asource of hot gas external of said vertical chamber, a conduit forconducting said hot gases from said source to said tubes, 21. secondconduit in communication with the discharge end of said tubes extendingupwardly through said vertical chamber, and shielded spaced orifices insaid second conduit for removal of vapor evolved from said wet material.

3. A wet sand dryer comprising a vertical drying chamber adapted toreceive wet sand at its upper end, a dry bin for receiving dry sand fromsaid vertical drying chamber extending from and disposed beneath saidvertical drying chamber, means for effecting the release of dry sandfrom said dry bin, two super-imposed horizontal rows of parallel metaltubes terminating at both ends in common plenums disposed intermediatethe vertical drying chamber and the dry bin, said upper row of tubesbeing widely spaced and said lower row of tubes narrowly spacedsuificient to permit only the passage of grains of dry sandtherethrough, a row of spaced baffle members having an inverted V shapeparallel to and mounted above said rows of tubes, a vertical stackextending upwardly through said vertical drying chamber andcommunicating at its bottom end with one of said plenums, shieldedspaced orifices in said stack for removal of water vapor evolved fromsaid wet sand, a source of hot combustion gases external of saidvertical drying chamber and said dry bin, and a conduit for conductingsaid hot combustion gases to said other plenum.

4. A dryer for drying wet granular material, including in combination avertical drying chamber adapted to receive wet granular material at itsupper end, rows of tubes disposed near the bottom of said chambercomprising an upper row of tubes widely spaced and a lower row of tubesspaced sufiiciently to permit only the passage of grains of dryingmaterial therethrough, a source of hot gas external of said verticalchamber, a conduit for conducting said hot gases from said source tosaid tubes, a second conduit in communication with the discharge end ofsaid tubes extending upwardly through said vertical chamber, andshielded spaced orifices in said second conduit for removal of vaporevolved from said wet material.

JOHN P. BRUNSCl-IWYLER.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 112,118 Buckingham Feb. 28, 1871363,865 Wales May 31, 1887 652,369 Merriman June 26, 1900 685,336 Leroyet a1. Oct. 29, 1901 695,004 Speer Mar. 11, 1902 731,682 Hillig June 23,1903 980,387 Yeo Jan. 3, 1911 2,333,089 Burkhardt Nov. 2, 1943

